Invacom C/L LBNF - getting both at the same time.

[guapoharry]

On one of those Invacom LNBFs with two C and two L ports, I am seeing what looks like circular TPs when I scan a linear satellite.

Specifically, I am scanning 111.1ºW Anik. (it's my TS bird) What comes in is a scrambled TP 12224H 20000, 7970V, 7971A that lncludes $NOTAX channel - Congress-Stop Unfair Satellite Tax. Don't see how this could come from anywhere than from the circular satellite at 110ºW.

Linear TPs from 111.1 do come in (albeit scrambled) as expected.

This is on a dish where a DiSEqC switch is used to select the C or L ports. Checked my receiver setup and it looks OK, L on port one. Turned off the receiver and disconnected the cable from the C port and then scanned again. 12224H still comes up.

Shouldn't the LNBF reject circular signals on the linear port? Do I have a bad Invacom unit?

 

[stogie5150]

Shouldn't the LNBF reject circular signals on the linear port? Do I have a bad Invacom unit?

No. A linear LNB can pick up some circular signals. Mine do it all the time. Now, most likely, they will be weaker, but they still will come through.

An other issue might be bleed through, when using the diseqc switch, whereby voltage and signal leeches through to all the ports. I have heard of that happening, too.

Nothing to be concerned about, IMO.

 

[Smith P.]

That combo design can't totally reject 12.2-12.7 GHz while you are on 11.7-12.2 GHz range and yes, linear part could get circular signals ( see that Dish thread when 118.75W begin working).

Those side tpns you could see easily if you will use spectrum analyzer ( BLSA will works fine also ).

 

[gillham]

Yes, the BLSA does work great!
See the attached scans on my Invacom's linear port of 91W and 101W respectively.

 

[Mr Tony]

depending on which receiver you use, it may blind scan in

The Pansat I have scans IF 950-1600 which with a LNB LO of 10750 is 11700-12350. So when I scan a satellite near a DBS one (79, 83, 91, etc) the blind scan does pick up the 1st 7-8 TP's from DBS.

Coolsat doesnt because the frequency scan is from 11700-12200

 

[Tron]

I've always had that issue with my Invacom QPH-031. The workaround for me is to simply scan "FTA only" when I am near a DBS bird, which usually rejects the unwanted channels. 119w is so powerful that it can show up 2-3 degrees in either direction on a blind scan...

 

[Sadoun]

I've always had that issue with my Invacom QPH-031. The workaround for me is to simply scan "FTA only" when I am near a DBS bird, which usually rejects the unwanted channels. 119w is so powerful that transponders from it can show up 2-3 degrees away in either direction on a blind scan...

+1

 

[Mr Tony]

tron your computer is possessed again with the 5 minute intervals of the same post

 

[Tron]

Got it this time, post deleted. I have no idea what's causing this...

 

[guapoharry]

Makes sense to select FTA. But then, wouldn't that eliminate finding channels that appear to be CI or encrypted, but are really in the clear?

 

[gillham]

Makes sense to select FTA. But then, wouldn't that eliminate finding channels that appear to be CI or encrypted, but are really in the clear?

Yup. I would suggest just scanning 11700 to 12200 as Iceberg mentioned. It will make your scans much quicker as well since you're scanning twice as much as you need to if your receiver is defaulting to 11700 - 12700.

My Coolsat 7000 defaults to 11700 - 12700. My Coolsat 6000 defaults to 11700-12200 when you have a linear LNBF setup and to 12200-12700 when you have circular setup. So it does the "right thing" like you would expect.

Another reason I like the Coolsat 6000 so much.

 

[Mr Tony]

My Coolsat 7000 defaults to 11700 - 12700.

visionsat does the same thing